DragonFly On-Line Manual Pages
Tk_CanvasPs(3) Tk Library Procedures Tk_CanvasPs(3)
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NAME
Tk_CanvasPsY, Tk_CanvasPsBitmap, Tk_CanvasPsColor, Tk_CanvasPsFont,
Tk_CanvasPsPath, Tk_CanvasPsStipple - utility procedures for generating
Postscript for canvases
SYNOPSIS
#include <tk.h>
double
Tk_CanvasPsY(canvas, canvasY)
int
Tk_CanvasPsBitmap(interp, canvas, bitmap, x, y, width, height)
int
Tk_CanvasPsColor(interp, canvas, colorPtr)
int
Tk_CanvasPsFont(interp, canvas, tkFont)
Tk_CanvasPsPath(interp, canvas, coordPtr, numPoints)
int
Tk_CanvasPsStipple(interp, canvas, bitmap)
ARGUMENTS
Tk_Canvas canvas (in) A token that identifies a canvas
widget for which Postscript is
being generated.
double canvasY (in) Y-coordinate in the space of the
canvas.
Tcl_Interp *interp (in/out) A Tcl interpreter; Postscript is
appended to its result, or the
result may be replaced with an
error message.
Pixmap bitmap (in) Bitmap to use for generating
Postscript.
int x (in) X-coordinate within bitmap of left
edge of region to output.
int y (in) Y-coordinate within bitmap of top
edge of region to output.
int width (in) Width of region of bitmap to
output, in pixels.
int height (in) Height of region of bitmap to
output, in pixels.
XColor *colorPtr (in) Information about color value to
set in Postscript.
Tk_Font tkFont (in) Font for which Postscript is to be
generated.
double *coordPtr (in) Pointer to an array of coordinates
for one or more points specified
in canvas coordinates. The order
of values in coordPtr is x1, y1,
x2, y2, x3, y3, and so on.
int numPoints (in) Number of points at coordPtr.
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DESCRIPTION
These procedures are called by canvas type managers to carry out common
functions related to generating Postscript. Most of the procedures
take a canvas argument, which refers to a canvas widget for which
Postscript is being generated.
Tk_CanvasPsY takes as argument a y-coordinate in the space of a canvas
and returns the value that should be used for that point in the
Postscript currently being generated for canvas. Y coordinates require
transformation because Postscript uses an origin at the lower-left
corner whereas X uses an origin at the upper-left corner. Canvas x
coordinates can be used directly in Postscript without transformation.
Tk_CanvasPsBitmap generates Postscript to describe a region of a
bitmap. The Postscript is generated in proper image data format for
Postscript, i.e., as data between angle brackets, one bit per pixel.
The Postscript is appended to the result of interpreter interp and
TCL_OK is returned unless an error occurs, in which case TCL_ERROR is
returned and the interpreter result is overwritten with an error
message.
Tk_CanvasPsColor generates Postscript to set the current color to
correspond to its colorPtr argument, taking into account any color map
specified in the postscript command. It appends the Postscript to the
interpreter interp's result and returns TCL_OK unless an error occurs,
in which case TCL_ERROR is returned and the interpreter's result is
overwritten with an error message.
Tk_CanvasPsFont generates Postscript that sets the current font to
match tkFont as closely as possible. Tk_CanvasPsFont takes into
account any font map specified in the postscript command, and it does
the best it can at mapping X fonts to Postscript fonts. It appends the
Postscript to interpreter interp's result and returns TCL_OK unless an
error occurs, in which case TCL_ERROR is returned and the interpreter's
result is overwritten with an error message.
Tk_CanvasPsPath generates Postscript to set the current path to the set
of points given by coordPtr and numPoints. It appends the resulting
Postscript to the result of interpreter interp.
Tk_CanvasPsStipple generates Postscript that will fill the current path
in stippled fashion. It uses bitmap as the stipple pattern and the
current Postscript color; ones in the stipple bitmap are drawn in the
current color, and zeroes are not drawn at all. The Postscript is
appended to interpreter interp's result and TCL_OK is returned, unless
an error occurs, in which case TCL_ERROR is returned and the
interpreter's result is overwritten with an error message.
KEYWORDS
bitmap, canvas, color, font, path, Postscript, stipple
Tk 4.0 Tk_CanvasPs(3)